feat: deliver durable live signal intents

internal/server/store/migrations.go

@@ -13,7 +13,10 @@ type migration struct {
 	sql     string
 }
 
-var migrations = []migration{{version: 1, sql: schemaV1}}
+var migrations = []migration{
+	{version: 1, sql: schemaV1},
+	{version: 2, sql: schemaV2},
+}
 
 func applyMigrations(ctx context.Context, db *sql.DB) error {
 	if _, err := db.ExecContext(ctx, `CREATE TABLE IF NOT EXISTS schema_migrations (
@@ -181,3 +184,15 @@ CREATE TABLE storage_counters (
 ) STRICT;
 INSERT INTO storage_counters(singleton, command_charged_bytes, charge_version) VALUES (1, 0, 1);
 `
+
+const schemaV2 = `
+CREATE TABLE signal_intents (
+  request_uuid BLOB PRIMARY KEY CHECK(length(request_uuid) = 16),
+  issue_uuid BLOB NOT NULL REFERENCES commands(issue_uuid) ON DELETE CASCADE CHECK(length(issue_uuid) = 16),
+  signal INTEGER NOT NULL CHECK(signal BETWEEN 1 AND 6),
+  command_revision INTEGER NOT NULL CHECK(command_revision > 0),
+  acknowledged INTEGER NOT NULL DEFAULT 0 CHECK(acknowledged IN (0,1)),
+  created_at INTEGER NOT NULL
+) STRICT;
+CREATE INDEX signal_intents_pending ON signal_intents(issue_uuid, command_revision, signal, acknowledged, created_at, request_uuid);
+`